Ultra high frequency resonator device



Jan. 6, 1948. E. D. MCARTHUR I 2,434,116

ULTRA HIGH FREQUENCY RESONATOR DEVICE Filed Dec. 29, 1944 a2 34 Flgl. ,829 ,9 2/ z Y Z8 /0 2a 26 50 5 I r 23 38 ,g a 3 be as Inventor:

Elmer D. MCATthUT,

by fl U W His Attorney.

Patented Jan. 6, 1 948 UNITED STATES PATENT OFFICE ULTRA HIGH FREQUENCYRESONATOR VICE Elmer ll). McArthur, Schenectady, N. Y., assignor toGeneral Electric Company, a corporation of New York 7 Claims.

My invention relates to ultra high frequency circuits employing cavityresonators and is concerned primarily with the provision of new andimproved circuits of this type having high power output.

It is an object of my invention to provide new and improved ultra highfrequency circuits of the cavity resonator type which utilize standingwaves of differing patterns in the resonator.

It is a further object of m invention to provide a new and improvedultra high frequency oscillator having high frequency stability, as wellas high power output.

It is a still further object of my invention to provide new and improvedultra high frequency circuits employing a plurality of electronic tubesin such a way that all contribute to a common power output system.

It is a still further object of my invention to provide new and improvedpush-pull ultra high frequency circuits.

In accordance with my invention, I provide improved ultra high frequencycircuits which employ two cavity resonators separated by the controlgrids of a plurality of electronic tubes and, by selective energizationof one of the cavity resonators, establish a standing Wave pattern inthe resonators of a desired type, the tubes being operated either inpush-pull or in parallel and all contributing to a common power outputsystem. In one of its aspects, the invention contemplates the use, in anultra high frequency oscillator, of a plurality of electronic tubesoperating in parallel to provide increased frequency stability, as wellas relatively large power output.

For a better understanding of my invention, reference may be had to thefolio-wing description taken in connection with the accompanying drawingand its scope will be pointed out in the appended claims. Fig. 1diagrammatically illustrates an embodiment of my invention as applied toan ultra high frequency amplifier; Fig. 2 is a diagrammatic illustrationof an embodiment of the invention as applied to an ultra highfreinvention as applied to an ultra high frequency amplifier whichcomprises a pair of cavity resonators defined by a hollow conductivecylinder I having a transverse conductive wall 2 located within thecylinder approximately at its mid point. The transverse metallic wallhas a pair of apertures 3, 4 in which are supported a pair of electronicdischarge devices 5, B. Each of the electron discharge devices 5, 6includes an anode "I, a cathode 8 and a control grid or electrode 9. Thecontrol grid, which affords a continuous span across the associatedaperture, is supported by transverse metallic disk I0 which ismaintained in position in the apertures 3, 4 by any suitable meansillustrated conventionally as the spring finger arrangement I I.

A pair of conductors I 2, I3 are conductively connected to the anodes ofthe devices 5, 6, respectively, and extend in a direction parallel withthe axis of the conductive cylinder I and from the anodes of thesedevices to the region outside of the cylinder I, A pair of tubularconductors I4, I connected to the cathodes 8 of the devices 5, 6,respectively, for high frequency alternating currents are arrangedparallel to the axis of the cylinder I and extend in a directionopposite to that of the conductors I2, I3. Moreover, conductors I4, I5preferably are substantially coaxially aligned, respectively, with theconductors quency oscillator; Figs. 3-5 show the'variations in standingwave patterns which may be obtained in cavity resonators similar tothose employed in the systems of Figs. 1 and 2 by variation in thenumber of electronic tubes employed and different methods ofenergization; and Fig. 6 diagrammatically illustrates a modification ofthe invention employin an alternative form of cavity resonator.

Referring particularly to Fig. 1 of the accompanying drawing, I havethere illustrated the I2, I3. The cathodes 8 preferably are insulatedfrom conductors I4, I5 for unidirectional currents, and unidirectionaloperating potentials, as well as currents for heatin filaments (notshown) for the devices 5, 6, are supplied over the lead-in conductorsI6, I! which extend through the tubular conductors I4, I5. The ends ofthe conductors I2--I5 remote from the transverse wall 2 are supported inalignment with each other and with the electrodes of the devices 5, 6 bya pair of end walls I8, I9.

The construction thus described defines a pair of cavity resonators ofthe multi-conductor type, the cylinder I forming the outer conductor ofeach of the resonators, the conductors I2, I3 constituting the innerconductors of a first cavity resonator coupled with the space betweenthe anode and grid of the devices 5, 6, and the conductors I4, I5constituting the inner conductors of a second cavity resonator coupledwith the cathode-grid regions of the devices 5, 6. The

dimensions of these two cavity resonators may be adjusted by means of apair of tuning plungers or pistons 20, 2|. The piston 20 carries contactfingers 22 engaging the inner surface of cylinder I and contact fingers23, 24 engaging, respectively, the outer surfaces of conductors [2, I3.Tuning piston 2| similarly is provided with contact fingers 25-21 inconductive engagement, respectively, with the inner surface of cylinderI and the outer surface of conductor I4 and the outer surface ofconductor l5. Adjustment of the positions of the plungers 2E1, 2! forvarying the dimensions of the cavity resonators may be made by means ofthe rods 28, 29 attached to these tuning pistons.

In order that the ultra high frequency system of Fig. 1 may utilize theelectron discharge devices 5, 6 in push-pull arrangement foramplification of signals, a pair of input electrodes are provided andare illustrated as of the capacitive type. These electrodes compriseplates 30, 3| attached, respectively, to the inner conductors 32, 33 ofa pair of concentric transmission lines having outer conductors 34, 35.Means are also provided for the extraction of amplified signals from thecavity resonator coupled with the anode-grid region of the dischargedevices 5, 6 and are illustrated as comprising a coupling loop 35 havingone of its ends attached to the plunger 20 and its other end connectedto a conductor 31 which is centrally positioned within a tubularconductor 38 forming therewith an output transmission line of thecoaxial conductor type Alternatively, the input coupling means may be ofthe induction type rather than the capacitive type and may be similar inform to the output coupling loop 35.

Fig. 2 illustrates the circuit, arrangement of an ultra high frequencyoscillator in which the input electrodes shown in Fig. l are omitted andfeedback means in the form of a coupling loop 35 linking theelectromagnetic waves within the anode-grid cavity and the cathode-gridcavity is provided. In all other respects, the structure of Fig. 2 isthe same as that of Fig. l.

The multi-tube circuits shown in Figs. 1 and 2 take advantage of thefact that many standing wave patterns are possible in a transmissionlinein addition to that of the conventional coaxial system which hascylindrical symmetry; Fig. 3 illustrates the field pattern which existsin the cavity resonators of the circuit ofFig. 1 when the cathode-gridresonator is energized from a double-end feed or input source by meansof the probes 33, Si or some equivalent energizing means. Electronictubes 5, 6, with this feeding arrangement, operate in push-pull to excitthe anode-grid cavity resonators and establish the same electromagneticwave pattern in this resonator. The dimensions of each of the resonatorsare adjusted by means of the plungers 20, El to resonate at the inputfrequency. The output loop 38 preferably is located at a point of strongmagnetic field in the anode-grid cavity between the conductors l2, l3and linked with the electromagnetic fields at that point. With thisconfiguration of the cavities and arrangement of the conductors, each ofthe tubes 5, 6

contributes to the common power output system with a resultant increasein power output and stability of the system.

The field pattern of Fig. 4 is that established within the cathode-gridcavity resonator when the input probes 3%, 3i supplied with signals ofthe'same phase or when a single probe is used so that the electronictubes 5 and 5 operate in parallel. It is, of course, apparent that theoperatingfrequency of the system, when operating in parallel, isdilierent from that when'operatingin push-pull, since the wavepatternand mode of operation of the multi-conductor resonator requireenergy of a different frequency and excitation to operate with this wavepattern. While both the field patterns of Figs. 3 and 4 show the use ofa pair of probes for exciting the cavities, it is apparent that an inputor driving loop similar to that of the output loop 33 may be employed inthe cathode-grid resonator to excite the resonator, especially when thesystem is operated from a single-ended feed line.

It is apparent that the ultra high frequency circuits of my inventionmay employ more than two electronic tubes and more than two innerconductors in each of the cavity resonators. The field pattern of Fig. 5illustrates the configuration, of the electronic waves within a cavityresonator which employs four symmetrically placed electronic deviceswhich are operating in push-pull. Each of the devices in thisarrangement contributes its full power to the output circuits of thesystem resulting in increased output and frequency stability.

My invention is applicable likewise to systems in which the cavityresonator-forming conductive member may have configurations other than.that shown in Fig. 1. Fig. 6 illustrates one such variation in which theouter conductive member 48 of the cavity resonator structure iselliptical in form. In this instance, the inner conductive rods 4|, 42,which are contained in the input cavity resonator for example and areconnected to the cathodes of the electron discharge devices, are locatedat the foci of the ellipse. The conductors 4|, 42 may likewise beelliptical in configuration. The cavity resonator formed bythe members4l42. is energized by an input coupling loop 43 similar to loop 36 ofFig. 1 and which may extend through the tuning piston of the cavityresonator. While the operation of such a system is essentially the sameas that of the previously described modifications, the use of theelliptical members lends to stability and ease in maintaining the systemoperating in the push-pull mode.

While I have shown and described my invention as applied to particularsystems embodying various devices diagrammatically shown, it will beobvious tothose skilled in the art that changes and modifications may bemade without depart-- ing from my invention and that Ithereforecontemplate in the appended claims to cover all such changes andmodifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secur by Letters Patent or" the UnitedStates is:

1. An ultra high frequency system comprising a hollow conductivecylinder, a transverse wall located within said cylinder having aplurality of apertures, an electron discharge device extending througheach of said apertures, each of said devices having a grid constitutinga conductive extension of said wall across the associated aperture andan anode and a cathode disposed on opposite sides of said wall,conductors connected to the anodes of said devices extendinglongitudinally within said cylinder in parallel relation to the axisthereof and constituting with said cylinder a first cavity resonator onone sideof said transverse wall, conductors connected to the cathodes ofsaid devices extending longitudinally within said cylinder in parallelrelation to the axis thereof and constituting with said cylinder asecond cavity resonator on the opposite side of said transverse wallfrom said first cavity resonator, and conductive means constitutingadjustable end walls for said resonators.

2; A resonator device comprising a grid-cathode resonator and agrid-anode resonator, a hollow conductive cylinder constituting a commonouter wall of said resonators, a transverse wall-within said cylinderhaving a plurality of apertures and constituting a common end wall ofsaid resonators, a plurality of conductors on each side of saidtransverse wall extending longitudinally within said cylinder andparallel thereto constituting inner members of said resonators, aplurality of electron discharge devices extending one through each ofsaid apertures, each of said devices having a grid conductivelyconnected to said transverse wall, and a cathode and an anode positionedrespectively in said grid-cathode and grid-anode resonators andconductively coupled each to one of said conductors, and push-pull inputelectrodes coupled to said grid-cathode resonator for exciting saidgrid-cathode resonator in push-pull pattern.

3. A device as in claim 2 in which said input electrodes are adapted tobe energized in phase opposition.

4. A device as in claim 2 in which said input electrodes are adapted toexcite said grid-cathode resonator with a signal to be amplified, andincluding output means coupled to said grid-anode resonator for derivingan amplified signal therefrom.

5. An ultra high frequency device comprising a hollow conductivecylinder, a transverse wall located within the cylinder and having aplurality of apertures, a plurality of electron discharge devicesextending one through each of said apertures, each of said deviceshaving a grid constituting a. conductive extension of said wall acrosssaid each of said apertures, said devices having anodes disposed on oneside of said transverse wall and cathodes on the opposite side thereof,conductors connected to the anodes of said devices extendinglongitudinally within said cylinder in a direction parallel to the axisthereof and constituting with said cylinder a first cavity resonator onone side of said transverse wall, conductors connected to the cathodesof said devices and extending longitudinally within said cylinder in adirection parallel to the axis thereof and constituting with saidcylinder a sec-- 0nd cavity resonator on the opposite side of saidtransverse wall from said first cavity resonator, and push-pull inputelectrodes coupled to said second cavity resonator for exciting the samein push-pull pattern.

6. A device as in claim 5 in which said input electrodes are adapted tobe energized in phase opposition.

7. A device as in claim 5 including conductive means constitutingadjustable end walls for said first and second cavity resonators.

ELMER. D. McARTHUR.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,284,405 McArthur May 26, 19422,381,320 Tawney Aug. 7, 1945 2,400,753 Haefi May 21, 1946 2,408,927Gurewitsch Oct. 8, 1946

